Partial support is requested for the 22nd Penn State Summer Symposium in Molecular Biology, a conference entitled "Chromatin Structure and Transcription." The conference will be held July 30-August 2, 2003 at the Nittany Lion Inn on Penn State's University Park campus. The past decade has witnessed burgeoning growth in realization of the importance of chromatin in all aspects of the function of DNA in eukaryotic cells. Two rapidly developing aspects of the role of chromatin in transcription will be the dual focal points for this meeting. First, histone modifications and their reversal have been implicated in gene regulation as activators and repressors have been shown either to be or to recruit, e.g. acetylases and deacetylases, respectively. Similarly, histone methylation, phosphorylation and ubiquitination are provided and/or recognized by transcription regulators and function as important epigenetic marks. Mutations in retinoblastoma can disrupt the interaction of Rb with deacetylases and deacetylase inhibitors have shown some utility in treatment of certain tumors. Other chromatin structural transitions involved in either activation or repression of transcription occur at the hands of large multiprotein chromatin remodeling complexes, the best known of which is SWI/SNF. BRCA1 is associated with a human SWI/SNF-related complex. Sessions on histone modification and remodeling will involve leaders in these areas of research and will complement the keynote address by C. David Allis, the originator of the histone code hypothesis. Second, a broad spectrum of novel techniques is allowing meaningful study of long range interactions in the chromosome context and the role of nuclear structural organization in the functional expression of the genome. Approaches ranging from genetics to fluorescence recovery after photobleaching will be presented in two platform sessions on structure and nuclear organization and long range chromosome interactions. These sessions will complement the plenary lecture by Ulrich Laemmli. Concurrent afternoon platform sessions will allow 36 junior investigators to present their research to the conferees; these speakers will be chose from abstracts of their posters. A notable feature of the Penn State Symposia in their proximity to a large segment of East coast institutions and the low cost for students, making them particularly popular with and well attended by graduate students and post-doctoral fellows. [unreadable] [unreadable]